A memory connector may couple a memory module to a substrate, such as a motherboard. This coupling may provide a physical connection between the substrate and the memory module as well as an electrical connection between conductive contacts on the substrate and conductive contacts of the memory module. For example, a memory connector may carry single-ended signals between a substrate and a Double Data Rate (DDR) Dual Inline Memory Module (DIMM).
More specifically, a memory connector may connect a substrate contact that is associated with a single ended signal to a DDR DIMM contact that is also associated with the single ended signal. More than one DDR DIMMs may be daisy-chained per memory channel. Due to signal routing considerations, conventional memory connectors may be used in conjunction with a four-layer motherboard (e.g., two signal layers, a power layer and a ground layer) to support, for example, two memory channels and four DDR DIMMs.
Differential signaling may be preferable to the aforementioned single-ended signaling in some circumstances. Differential signaling requires two traces, two substrate contacts, and two memory module contacts per signal. Existing Fully-Buffered DIMMs and other proposed DIMM technologies support differential signaling at a limit of one DIMM per memory channel. Conventional memory connectors and a four-layer motherboard may support up to three memory channels, and therefore up to three of the existing or proposed DIMMs. More than four substrate layers (e.g., six, eight or ten layers) are required in order to support four or more of such DIMMs.